Model: R 47
Production  
Engine  
Power transmission  
Electrical System  
Chassis  
Dimensions/Weights  
     
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Production
Begin of the Production   1927
End of the Production   1928
Numbers Produced   1720
Price   1.850,- RM
Engine
Internal Designation   M 51
Motor Type   four-stroke two-cylinder flat-twin
Bore x Stroke   68 x 68 mm
Displacement   494 ccm
Max Power   18 hp at 4000 rpm
Compression Ratio   5.8 : 1
Valves   ohv
Carburetion System   1 x carburettor,BMW Spezial two-valve 22 mm
Engine Lubricating System   forced-feed lubrication
Oil Pump   gear pump
Power Transmission
Clutch   single-plate, dry
Number of Gears   3
Shifting   manual
Gearbox Ratios   2.5 / 1.50 / 1.07
Rear Wheel Ratio   1 : 4.38 (with sidecar 1 : 5.7)
Bevel / Crownwheel   13 / 57 teeth (with sidecar 10 / 57)
Electrical System
Ignition System   Bosch magneto ignition
Generator   magneto generator on request
Spark Plugs   Bosch W 175
Chassis
Designation   R 47
Frame   twin-loop steel tubular frame
Front Wheel Suspension   plate spring, 5 laminae
Rear Wheel Suspension   rigid
Wheel Rims   CC 1
Tyres front   27 x 3.5 low pressure or 26 x 3 high pressure
Tyres rear   27 x 3.5 low pressure or 26 x 3 high pressure
Brakes front   drum brake Ø 150 mm
Brakes rear   external shoe brake at gearing (on cardan shaft)
Dimensions/Weights
Length x Width x Height   2100 x 800 x 950 mm
Wheel Base   1410 mm
Fuel Tank Capacity   14 l
Unladen Weight, Full Tank   130 kg (with original sidecar 192 kg)
Top Speed   110 kph